JP2929856B2 - Fluorescent display tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube, and more particularly to a flat type fluorescent display tube.

[0002]

2. Description of the Related Art As shown in FIG. 3, heat-resistant and insulating materials such as glass are used for an anode substrate 1, as shown in FIG. I have.
On this, a wiring, a base electrode, a phosphor layer and the like are sequentially laminated and printed. The electrode assembly 2 was made of 42% Ni-6% Cr-residual Fe
The grid 3 is made of an alloy (hereinafter referred to as 426) and welded. Further, a plurality of filaments 4 are suspended in parallel with the grid 3 at a predetermined interval.

The cover glass 5 is made of a sheet glass, which is a light-transmitting insulating material. A part of the cover glass 5 is provided with an exhaust pipe 6 which is a thin tube for evacuation.

[0004] The fluorescent display tube is completed by hermetically sealing these parts together and making the inside of the exhaust tube vacuum.

[0005]

The fluorescent display tube is a kind of vacuum tube, and is manufactured in an air-conditioned room in which dust and the like are sufficiently controlled. However, the manufacturing process of the fluorescent display tube is generally long, and there is a possibility that foreign matter remains in the fluorescent display tube. The residual foreign matter in the tube is classified into a conductive substance, an insulating substance, a mobile substance, or a fixed substance. However, there is a problem that the display of the fluorescent display tube is obstructed in various forms.

For example, when an insulating foreign substance adheres to the phosphor layer, display defects such as uneven brightness, missing dots in which a part of the display is lost, and black spots occur. In the case of conductive foreign matter, erroneous lighting may occur due to a short between grids, a short between anodes, or the like. The most problematic is the case of a mobile substance, which moves in the tube, and may or may not be abnormal depending on the attachment site. Once a product is determined to have no abnormality, it may become abnormal during use, and measures against mobile foreign matter are the most important issues.

SUMMARY OF THE INVENTION It is an object of the present invention to provide brightness unevenness, missing dots,
An object of the present invention is to provide a fluorescent display tube capable of preventing occurrence of erroneous lighting due to display defects such as black spots, short circuit between grids, short circuit between anodes, and the like, and preventing occurrence of abnormalities due to mobile substances.

[0008]

According to the present invention, there is provided an anode substrate in which wiring, a base electrode, and a phosphor layer are sequentially formed on a plate glass, a grid disposed on the anode substrate, and a grid fixed thereto. A fluorescent display tube comprising: an electrode assembly having a filament suspended at regular intervals; and a cover glass sealed to the anode substrate to form a vacuum container.
Peripheral portion of the outer surface of the anode substrate excluding the back surface of the phosphor layer
A concave portion is provided in a part of the minute, and a magnetic body is fitted and fixed in the concave portion. Here, the recess may constitute an exhaust hole.
You.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the present invention.

The constituent materials and manufacturing process of the first embodiment are the same as those of the conventional fluorescent display tube shown in FIG.

In the first embodiment, as shown in FIG. 1, a commercially available plate glass is used for the anode substrate 11, and after a process such as cleaning, an anode wiring is formed with Ag or the like using a conventional technique. I do. Next, the base electrode and the like of the phosphor layer 13 are formed by printing, and finally the phosphor layer 13 serving as an anode is printed to complete the anode substrate 11.

Next, the electrode assembly 2 is formed by etching or the like.
The electrode assembly 2 is manufactured by using a 26 alloy or the like according to the shape of the anode substrate 11, and the grid 3 is bonded to the electrode assembly 2 by welding or the like, and then the filament 4 is suspended. After that, the anode substrate 1
1, the electrode assembly 2 and the cover glass 5 are hermetically sealed as in the prior art, and an exhaust pipe (not shown) is attached to evacuate the inside. Thus, the fluorescent display tube is completed.

In the first embodiment, when the anode substrate 11 is formed, the concave portion 1 is formed on the outer surface of the sheet glass opposite to the electrode forming surface.
7 is provided, and a magnetic body 18 is fitted into the concave portion 17 to form a trap portion 19 fixed with an adhesive 22.

By forming the trap portion 19, it is possible to capture conductive mobile foreign matter generated by welding or the like from the electrode assembly 2 in the fluorescent display tube. That is, the mobile foreign matter approaching the trap portion 19 is attracted and captured by the magnetic field. In addition, the mobile foreign matter existing at a place distant from the trap portion 19 can be easily captured by applying vibration or the like to the fluorescent display tube. In this case, the concave portion 17 is arranged at a position that does not affect the electron trajectory, and the magnetic body 18 is adjusted to a strength that does not affect the electron trajectory.

FIG. 2 is a sectional view of a main part of a second embodiment of the present invention.

In the second embodiment, as shown in FIG. 2, a magnetic body 18 is fitted into an exhaust hole 20, a lid 21 is adhered to fix the magnetic body 18, and a vacuum is maintained. .

In both the first and second embodiments, a so-called ferromagnetic material, silicon steel plate, permalloy, ferrite, or the like can be used as the magnetic material 18.

[0019]

As described above, the present invention has been a conventional problem by trapping a conductive foreign substance by a trap portion in which a magnetic substance is fitted and fixed in a recess formed in the anode substrate in advance. This has the effect of preventing display disturbances caused by mobile foreign matter. At least, it can be expected to decrease by one digit compared to the conventional display failure occurrence rate.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a second embodiment of the present invention.

FIG. 3 is a partially cutaway perspective view of an example of a conventional fluorescent display tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Anode substrate 2 Electrode assembly 3 Grid 4 Filament 5 Cover glass 6 Exhaust pipe 13 Phosphor layer 17 Concave portion 18 Magnetic material 19 Trap section 20 Exhaust hole 21 Lid

Claims (2)

(57) [Claims] An anode substrate in which wiring, a base electrode, and a phosphor layer are sequentially laminated on a sheet glass, a grid is fixed on the anode substrate, and filaments are provided on the grid at regular intervals. In a fluorescent display tube having a suspended electrode assembly and a cover glass sealed to the anode substrate to form a vacuum vessel, an outer surface of the anode substrate except for a back surface of the phosphor layer is provided. A fluorescent display tube, wherein a concave portion is provided in a part of a peripheral portion, and a magnetic body is fitted and fixed in the concave portion. (2) That the recess forms an exhaust hole.
The fluorescent display tube according to claim 1, wherein: